Locks for bracelets



Apz'ifi 9, 1968 BRUNET 3,376,619

LOCKS FOR BRACELETS Filed June 24, 1966 we go INVENTOR Lou/s BRUNET' 2 3I 4 iffy/0x 1 Unite States Patent 3,376,619 LOQKS FOR BRACELETS LouisBrunet, Annecy-le-Vieux, France, assignor to Societe Zuccolo, Rochet 8:Cie, Annecy, Haute- Savoie, France, a corporation of France Filed June24, 1966, Ser. No. 560,190 Claims priority, application France, June 30,1965,

22, 1 Claim. (Cl. 24-241) ABSTRACT OF THE DISCLOSURE This inventionrelates to resiliently extensible couplings for connecting the ends of abracelet, watch strap or belt of the type in which one end is equippedwith a resilient hooking and locking device engaging -a transverse barattached to the other end of the strap.

This kind of booking or locking device usually c0mprices a frameattached by one of its transverse edges to the end of the watch strap,and within this frame there is guided, to slide longitudinally, that isto say in the direction of the length of the watch strap or bracelet andagainst the influence of a spring, a flat sleeve mounted astride thesecond transverse edge of the frame. On this sleeve there is hinged acover which engages with a slotted bar attached to the other end of thestrap, said cover being capable of folding back on to the sleeve, withwhich it locks, enclosing the bar.

A lock of this kind is rather thick and is not suitable for watch strapsfor very thin watches.

To eliminate this disadvantage the resilient lock according to theinvention, which is of the type having a bar attached to one end of thewatch strap, and a hooking or locking device which is attached to theother end of the strap and engages with said bar, is characterized inthat said hooking or locking device consists of two flat elements, whichslide the one within the other after the manner of a drawer in a chestof drawers, said elements containing between them a spring, thearrangement being such that the open faces of said sliding elements facein opposite directions and wherein the external sliding element isequipped in its open face with two longitudinal guide rails forretaining the internal sliding element, to which is attached a lockingplate engaging with said bar and which, when in the locked position,rests between said longitudinal guide rails without adding any extrathickness.

In a preferred version of the invention, the locking plate is hinged tothe internal sliding member by means of a transverse spindle and a gapis left between said spindle and the edge of the sliding member toaccommodate the bar, the total height of the hinge being no greater thanthe height of the internal sliding member.

This gap or throat is preferably formed by bending the adjacenttransverse edge of the internal sliding member at the level of thebottom of the external sliding member, in such a way that there is atthe same time formed a mechanical stop for limiting the travel of theinternal sliding member when the latter is fully retracted.

Finally, the length of the internal sliding member,

measured in the longitudinal direction of the bracelet or strap, is lessthan the length of the external sliding memher by an amount sufficientto leave a gap, between the end of the internal sliding member when thelatter is fully retracted and the bar which attaches the externalsliding member to the watch strap, to accommodate the locking lip of thelocking plate, which preferably displays instructions indicating thedirection of movement for opening the lock.

In this way there is obtained a lock which is very fiat, the totalheight being less than half that of the previously known locks.

There will now be described by way of example and with reference to theattached drawings, a version of the lock according to the invention.

In the drawings:

FIGURE 1 is a perspective view or" the lock in the open position,showing the two strap ends of the bracelet,

FIGURE 2 is a longitudinal cross-section of the lock in the closedposition.

FIGURE 3 is a perspective view of the spring.

The exploded view of FIGURE 1 shows how end 1 of the bracelet terminatesin a stirrup 2 which has two arms 3 and 4- at the sides, joined togetherby a. bar '5, adapted to engage with the lock. The latter is hinged tothe other end 6 of the bracelet or strap by means of hinge 7 throughwhich passes spindle 8 fixed to the lock.

The lock comprises slider 10 which slides inside guide frame 9, thesetwo parts having openings facing in opposite directions, for example theopening of the slider .10 faces downwards whereas that of the guideframe 9 faces upwards.

The guide frame 9 has a bottom 11 and two side guides 12 and 13, whichterminate in two extended edges 14 and 15 situated in a plane parallelto the bottom 11 of the guide frame and running longitudinally, that isto say in the direction of the length of the bracelet.

These guiding edges 14 and 15 do not extend far across the width of thebracelet, but extend far enough to form retainer rails for the slider10, the arrangement being such that the slider 10 can slide in guidedfashion within the guide frame 9. The slider 10 has a flat body portionwith two flanks 14' and 15'. Between the front wall 16 of the slider 10and rear wall 17 of the guide frame 9 there is a flat coil spring whichpushes the slider 10 inwards in the guide frame 9 in the directiontoward the hinge 7.

This coil spring is represented on a larger scale in FIGURE 3, andconsists of a steel wire 25 coiled to conform to the internalcross-section of the lock.

The slider 10 has a rear portion 18 bent into L-shape and terminating ina bent sleeve 19 which accommodates pin 20 and thus forms the centralbush of the hinge for locking plate 23. Two outer bushes 21 and 22 ofthis hinge are formed by bending around the ends of the locking plate23. Thus the locking plate 23 forms a cover plate for the lock, and itsresilient lip 24 engages, when the lock is closed, over the edge of thefront face 16 of the slider 10. The width of the locking plate 23, whichis made of rather thin sheet metal, is equal to the distance between thetwo retainer flanges 14 and 15, so that the plate 23 just fits betweenthese two flanges. To join together the two ends of the bracelet andclose the lock, the locking plate 23 is first introduced between the bar5 and the stirrup 2. The locking plate 23 is then swung inwards,bringing the bar 5 to rest in the recessed rear portion 18 of slider 10.Further rotation of the locking plate 23 brings it down between theedges of the retainer flanges 14, 15 whereby no increased thickness ofthe lock results, as shown in FIGURE 2, which illustrates the lock inthe closed position. The spring 25 pushes the slider It all the way intothe guide frame 9.

FIGURES 1 and 2 show how the retainer flanges 14 and 15 terminate shortof the hinge 7 to leave a gap 27 between the front edge 26 of thelocking plate 23 and the hinge 7, said gap being wide enough for thewearer of the bracelet or strap to insert his fingernail in order toopen the lock.

, The advantage provided by the lock described here, applied to abracelet consisting of articulated elements, bearing in mind that it canif desired be applied to a bracelet of another kind or to a belt or thelike, is that the lock is very thin due to the arrangement of a slidersliding within a guide frame after the manner of a drawer in a chest ofdrawers, and wherein the cover plate rests between the two guidingflanges of the guide frame without producing any extra thickness.

I claim:

1. A resiliently extensible lock, particularly for watch straps, of thetype which comprises a bar attached to one end of the bracelet, and ahook or lock attached to the other end of the bracelet or watch strapand engaging with said bar, the lock including a hooking or lockingdevice consisting of two fiat elements which slide the one within theother after the manner of a drawer in a chestof-drawers, and containingbetween them a spring wherein the two elements have openings facing inopposite directions and wherein moreover the external element in theform of a guide frame has in its open face two longitudinal guide railswhich act to retain an internal sliding member equipped with a lockingplate which engages with the bar and which, when the lock is closed,rests between the two guide rails without entailing any extra thickness,said locking plate being hinged to the internal sliding member bysuitable means so that there is left between said hinge and the end ofsaid internal sliding member a throat adapted to snugly accommodate thebar, wherein the total height of the hinge is no greater than that ofthe internal sliding member, said throat beingv ber being less than thatof the external guide frame by' an amount sufficient to leave a gap,when the internal sliding member is fully retracted, between the frontedge of the internal Sliding member and the attachment bar which securesthe other end of the bracelet to the external guide frame, toaccommodate the locking clip of the locking plate, said bar having ,afiat surface abuttingly engageable with the said transverse edge of theinternal slider to prevent flexing of an attached watch strap fromcausing the said bar to pivot upwardly about the hinge means asufficient amount to engage the under surface of the locking plate andinadvertently unlock the lock.

References Cited UNITED STATES PATENTS 1,852,462 4/1932 Johnson 24711,892,281 12/1932 Kestenman. 2,006,047 6/1935 Johnson 2471 2,333,048 10/1943 Schoeninger 24239 DONALD A. GRIFFIN, Primary Examiner.

